Piston skirt expander



March 20;, w34. L] M. BRANNAN 2,951,859

PISTON SKIRT EXPANDER Filed April.l l2, 1955 OHL Patented an. 20, i934 PISTON SKIRT EXPER Application April 12, 1933, Serial No. 665,734

Claims.

My invention relates to means for expanding split skirts of pistons for internal combustion engines and the like.

The principal object of my invention is to g provide a simple and novel piston skirt expander formed of at spring metal and comprising sections which are connected together by cross braces.

Further objects and advantages of my inven- 1@ tion will appear from the following description taken in conjunction with the accompanying drawing in which:

Figure 1 is a bottom plan view of a piston having one form of my improved expander applied thereto;

Fig. A2 is a side view of the expander; and

Fig. 3 is a side View ofthe strip of spring steel before it is bent or formed to provide a half-section of the expander.

Referring to Fig. 1, piston skirt 7 is provided with a vertical slot 8 and piston pin bosses 9 through which extends the usual piston pin 10. The piston may be of any of the-well known types, such, for example, as is shown in United States Patent No. 1,885,038, issued October 25, 1932. In most pistons formed of aluminum. or the like, the head is wholly or partially separated from the skirt by acircumferential slot or slots and the skirt is provided with a vertical slot to permit it to expand and" contract. It is in this general type of piston that my invention is peculiarly adapted for use.

The expander comprises two complementa and similar half-sections 12 each formed from a flat strip of spring metal shown in Fig. 3. The strip of steel is cut to provide two tongues.'13 and an intermediate prong 14 at each end. In shaping the strip into one half of the expander the center portion 15 is bowed slightly outwardly. The

tongues 13 are curvedconsiderably and their free ends 16 are curled or rolled inwardly. The

prongs 14 are curved considerably adjacent thel braces securing said half-sections together.

place with the side portions 15 firmly contacting and pressing in opposite directions against the facing edges of the bosses 9 and the tongues 13 pressing-at 19 against the piston skirt in opposite direction and approximately at right angles to the axis of the bosses 9. At one side the tongues 13 engage adjacent the vertical slot 8 in the piston skirt. The piston pin 10 extends through openings 20 in the sides of the expander. The edges of the tongues 13 where they engage the 65 piston skirt are preferably formed with sharp points or lips 18 which bite into the metal of the skirt and tend to retain the expander against displacement.

It will be apparent that the expander constantly expands the skirt so that the latter snugly ts the cylinder wall. The connected prongs 14 rmly secure the two halves together and facilitate their handling and these connected prongs also form cross braces which enhance the ei'ciency of the expander.

I claim:

l. A piston skirt expander formed of leaf spring metal and comprising two half -sections and spring `2. A piston skirt expander comprising two sections formed of spring metal having their end portions in contacting relation, and spring arms connecting the two sections together.

3. A- piston skirt expander adapted to extend across the skirt of a piston and comprising two half-sections having curved ends in contact with each other and formng expansion formations, and spring arms projecting from each section and secured together.

4. A piston skirt expander comprising two sections formed of leaf spring metal, each having at each end two tongues and an intermediate prong, the tongues on the two sections being in contacting relation and the prongs of the two sections being in overlapping relation, and means for fastening the overlapping prongs together.

5. A piston skirt expander comprising two complemental sections eachV formed of leaf spring and each having at each end a bowed prong and 1.53 at least one bowed tongue with an inwardly curved end. thecurved ends of the two sections being in firm contact with each other and the prongs of the two sections being within the expander and connected together at their ends.

LEE M. BRANNAN. 

